This characterization of colloidal particles, particularly spheres, is an important and pervasive issue in many aspects of industrial chemical, physical and biomedical applications. A variety of important functionalities are being sought to perform various characterizations including 1) bead based molecular binding assays, 2) flow field measurements, 3) automated particle image detection in holograms, and 4) real time analysis of particle features. For example, coherent illumination traditionally has not been used widely for particle image velocimetry because the resulting holographic images can be difficult to interpret quantitatively. Consequently, measurements of fluoroscence yield has been used to carry out bead based molecular binding assays using holographic imaging in one color. However, such methods require fluorescent labeling with conventional assays requiring tens of thousands of beads to eliminate artifacts to non-specific fluorospore binding and unintentional bleaching. It has been recently demonstrated that holographic video microscopy images of colloidal particles can be used to locate the particles' centers in three dimensions, even when particles occlude each other along the optical axis. Earlier demonstrations using phenomenological models for the observed scattering patterns achieved tracking resolution comparable to that attained with conventional particle imaging methods. The principal benefit of coherent illumination in these studies was the greatly extended working distance and depth of focus compared with conventional imaging methods. However, these methods are inefficient, do not allow any real time analysis to be performed and cannot even perform a number of characterizations (such as the four listed above). Consequently, characterizations mentioned above have not been possible heretofore, have not been commercially feasible or problems remain without apparent solution.